The present invention relates generally to methods and devices for alerting the operator(s) of a vehicle about conditions effecting the operation of the vehicle.
Over the past several years, a number of sophisticated flight hazard warning systems have been developed for aircraft which have contributed substantially to flight safety. These systems include ground proximity warning systems (GPWS), enhanced ground proximity warning systems (EGPWS), traffic alert and collision avoidance system (TCAS), and windshear detection systems.
The primary purpose of GPWS and EGPWS is to monitor an aircraft""s position relative to terrain and prevent controlled flight into terrain (CFIT) accidents. With features such as look-ahead capability, verbal alerts, and terrain display on the aircraft""s weather radar display or the electronic flight instrument system, the flight deck crew can gain situation awareness of the terrain in their immediate vicinity. Typically, a verbal alert, xe2x80x9cCaution Terrain,xe2x80x9d will be first enunciated approximately 60 seconds from the collision point. This alert comes even earlier than a minute if the terrain is particularly high above the aircraft""s altitude. If the flight deck crew does not change course and the aircraft gets within 30 seconds of the terrain (or obstacle) a second verbal alert, xe2x80x9cTERRAIN, TERRAIN, PULL UP!xe2x80x9d is issued.
For the most part, TCAS is designed to function as a backup to air traffic control and the see-and-avoid subjective method for traffic separation. Generally, the system is designed to examine the area in the vicinity of the aircraft, provide visual and aural advisories and alerts to the flight deck crew about traffic that impose a threat to safe and legal separation, and recommend the least disruptive vertical maneuver to achieve safe separation. The degree of threat imposed by the intruder is generally indicated through aural and visual cues with symbols that are redundantly color coded. In one commonly used system, a xe2x80x9ctraffic advisoryxe2x80x9d (TA) is displayed and the verbal alert xe2x80x9cTRAFFICxe2x80x94TRAFFICxe2x80x9d is issued when an intruder is within 20-48 seconds of the closest point of approach. If the separation distance decreases further and the intruder is determined to be within 15-35 seconds of a collision, a xe2x80x9cresolution advisoryxe2x80x9d (RA) is displayed and the flight deck crew is aurally commanded to fly a vertical maneuver to prevent a collision. Typical aural commands related to a RA include xe2x80x9cMONITOR VERTICAL SPEED,xe2x80x9d xe2x80x9cCLIMBxe2x80x94CLIMBxe2x80x94CLIMB,xe2x80x9d xe2x80x9cREDUCE DESCENDxe2x80x94REDUCE DESCEND,xe2x80x9d and xe2x80x9cDESCEND, DESCEND NOWxe2x80x94DESCEND, DESCEND NOWxe2x80x9d.
Because in most cases these systems operate independently of each other, it is possible under certain circumstances to get conflicting warnings from more than one system at about the same time. For instance, there are situations in which a GPWS and EGPWS generates an aural xe2x80x9cPull Upxe2x80x9d command followed immediately by the TCAS generating a xe2x80x9cDescendxe2x80x9d command. This type of situation can make it very difficult for the flight deck crew to make a timely determination of the correct response, especially considering the limited time available for responding to a given warning.
Several techniques have been proposed for addressing this problem. In one such approach, each flight hazard warning system generates both an inhibit signal and a warning alert signal, and the system is configured such that the inhibit signal from one selected hazard warning system is used to suppress alert signals from all other hazard warning systems. Since there are a very large number of potential flight hazards, each with varying criticality and associated probability of an accident, such a simplistic approach will be unlikely to provide optimal warnings of flight hazards.
Another disadvantage of current flight hazard warning systems is that they include several physically separate, independent, and discrete systems such as the GPWS, EGPWS, TCAS, a reactive windshear system (ReWS), and a predictive windshear system (PrWS). U.S. Pat. No. 6,002,347 (Daly et. al.) and U.S. Pat. No. 6,127,944 (Daly et. al.), both assigned to the assignee of this invention and hereby incorporated by reference, list some drawbacks of a federated approach, and propose methods to overcome such shortcomings. Both ""347 and ""944 provide an aircraft flight hazard avoidance system wherein concurrently generated warning signals are prioritized to provide a warning of the most critical flight hazard.
While the teachings of both ""347 and ""944 are useful for de-conflicting and resolving concurrently issued conflicting alerts originating from more than one hazard warning system, they do not appear to discuss methods for presenting the output of their system to the flight deck crew.
Since the flight deck crew needs to be aware of a significant number of events in the environment outside the aircraft, it is generally desirable to integrate and prioritize the incoming information into like categories, and present the information in a less confusing and de-conflicted manner.
The present invention provides methods and systems for filtering, integrating, and/or presenting information to the flight deck crew, preferably within a common framework. In one illustrative embodiment, flight hazard conditions detected by conventional systems including TCAS, GPWS, EGPWS, PrWS, ReWS, weather radar, etc., are analyzed and prioritized to resolve any conflicting warnings. Then, aural and/or visual presentation methods are used to aid the flight deck crew in circumventing the conditions. In one illustrative embodiment, two- or three-dimensional surround-sound techniques are used to emanate directional aural cues from strategic locations on the flight deck to aid in drawing the crew""s attention to one or more alerts. Alternatively, or in addition, some or all of the alerts may be presented graphically and/or textually on one or more visual displays on the flight deck.